With thanks to team photographers and Getty Images, please enjoy photos that have officials in the frame. Note how the officials are carrying their electronic whistles (either tied to their belt loops or tied with a wrist lanyard).
From team photographers (click on a photo to begin gallery):
From Getty Images:
Referee Adrian Hill
Officials Ron Torbert and James Coleman kneel during the National Anthem. Down Judge Jim Mello is in the background.
Line judge Mark Perlman
Referee Ron Torbert
Down judge Derek Bowers
Referee Shawn Hochuli
Referee Jerome Boger and down judge Julian Mapp.
Side judge Jonah Monroe
Down judge Sarah Thomas
Umpire Ramon George. Note the electronic whistle tied to his belt.